An optical communications repeater is used in a fiber-optic communications system to regenerate an optical signal. By reconstructing the signal before amplification, the. At their core, both optical fibre amplifier and repeaters have a similar goal: boosting the signal so that it can travel farther. However, the way they achieve this is radically different. Imagine a light signal traveling through miles of fiber optic cables. These devices are used to overcome the limitations of signal loss that occur over long distances or due to other factors such as noise or distortion.